When I got my first 622 (Feb '06) one of the local OTA DT's would not lock. Same as yours, high signal...no lock...red bar. I don't recall which it was. I called Dish (AHDTS) and told them of the issue, gave them the call letters and UHF frequency. 2 days later, it locked, and has worked ever since.
Several months later, when my second 622 was being installed, and my dish was upgraded to the 1000+, I asked the installer about it, when the second 622 locked on to all the locals, at the first attempt.
He told me there are literally hundreds of different OTA signals, and "most likely" the first 622 has some slightly incorrect information about the channel that would not lock. Once TS identified it, and corrected the information in the receiver, is when it locked.
I have no idea if what the installer told me is correct. What I do know is, 2 days after calling AHDTS, it worked, and has ever since.